Exposure-response relationship of neighbourhood sanitation and children's diarrhoea
Jung, Y.T.; Lou, W.; Cheng, Y.-L.
Tropical Medicine and International Health Tm and Ih 22(7): 857-865
2017
ISSN/ISBN: 1365-3156 PMID: 28449238 DOI: 10.1111/tmi.12886Document Number: 664336
To assess the association of neighbourhood sanitation coverage with under-five children's diarrhoeal morbidity and to evaluate its exposure-response relationship. We used the Demographic and Health Surveys (DHS) of 29 developing countries in sub-Saharan Africa and South Asia, conducted between 2010 and 2014. The primary outcome was two-week incidence of diarrhoea in children under 5 years of age (N = 269014). We conducted three-level logistic regression analyses and applied cubic splines to assess the trend between neighbourhood-level coverage of improved household sanitation and diarrhoeal morbidity. A significant association between neighbourhood-level coverage of improved household sanitation and diarrhoeal morbidity (OR [95% CI] = 0.68 [0.62-0.76]) was found. Exposure-relationship analyses results showed improved sanitation coverage threshold at 0.6. We found marginal degree of association (OR [95% CI] = 0.82 [0.77-0.87]) below the threshold, which, beyond the threshold, sharply increased to OR of 0.44 (95% CI: 0.29-0.67) at sanitation coverage of 1 (i.e. neighbourhood-wide use of improved household sanitation). Similar exposure-response trends were identified for urban and rural subgroups. Our findings suggest that neighbourhood sanitation plays a key role in reducing diarrhoeal diseases and that increase in sanitation coverage may only have minimal impact on diarrhoeal illness, unless sufficiently high coverage is achieved.